retrofitting with non-cfc substitutes

More documents

Recommendations

Info

RETROFITTING WITH NON-CFC SUBSTITUTES COMMERCIAL REFRIGERATION 1994 Allied Signals Chemicals. Refrigeration Report, An Update from Allied Signal on the Progress of Environmentally Acceptable Fluorocarbon Alternatives, page 2 & 3: Texas Supermarket Preparing for Future with Allied Signal's Genetron AZ-50. January 1994. Allied Signal and Copeland are working together, to ensure optimum system performance when retrofitting from R-502 to AZ-50, an azeotropic mixture of HFC-125/HFC-143a. The article describes a conversion of a supermarket from R-502 to AZ-50. The existing equipment, a ® Copeland 15 hp Discus 4D compressor, was cooling 32 feet of low-temperature, frozen-food display case. The equipment was checked for proper operation before the conversion; expansion-valve superheat, head pressure and oil pressure, suction pressure and temperature, discharge pressure, compressor amperage, voltage, and ambient temperature. No major modification was done with the equipment. The mineral oil was replaced with polyol ester-based lubricant. To reach the maximum remaining mineral oil content, five percent, the lubricant was changed three times, with 72 hours operation time between each change. Discharge pressure is about 20 psi higher with AZ-50 than with R-502, no other significant changes occurs. Future retrofits of similar systems are estimated to cost approximately US $ 1,500. 1993 UNEP IE: Catalogue of Technologies for Protecting the Ozone Layer, Refrigeration, Air Conditioning and Heat Pumps. Norway, 1993. HFC-134a is an alternative refrigerant to CFC-12 in cold storage. Studies show from 1% less to 7% higher energy consumption than CFC-12. Problem of finding suitable lubricants. HFC- 134a has very low solubility and mineral oil does not mix well in HFC-134a, which could contribute to the following problems: poor oil return back to the compressor, resulting in possible compressor failure fouling of expansion valves and heat exchanger surfaces, leading to reduced system performance Lawson, C. Curtis, DuPont Fluorochemicals: Alternative Refrigerants for Retrofit of Existing CFC-12 and R-502 Commercial Refrigeration Systems. Presented at the International Conference on CFC and Halon Alternatives, Beijing, P.R.C, April 20-23, 1993. The paper provides an overview of the alternative refrigerant candidate from DuPont, and discuss retrofit procedures and equipment retrofit experiences with alternatives for servicing existing CFC-12 and R-502 refrigeration equipment. Over 5000 super markets and restaurants has been converted successfully into DuPont's alternative refrigerants. 36
RETROFITTING WITH NON-CFC SUBSTITUTES CFC-12: MP39 for medium temperature stationary equipment, down to -23°C. Comparable capacity. Alkylbenzene lubricant. MP66 for low temperature, below -23°C (and as replacement for R-500 in medium temperature applications). Comparable capacity. Alkylbenzene lubricant. MP52 for automotive air conditioning systems. HFC-134a. Requires more extensive system preparation and equipment modifications than the blends. Lower capacity, might require a bigger compressor for low temperature systems. Polyol ester lubricant required, two-three oil flushes. R-502 HP80 Comparable capacity and discharge temperature, preferable when high discharge temperature might be a problem. Alkylbenzene lubricant. Polyol ester can also be used, but require two-three oil flushes. HP81 Slightly higher efficiency. Alkylbenzene lubricant. Polyol ester can also be used, but require two-three oil flushes. HP62, longterm alternative (does not contain HCFC). Requires more extensive system preparation. Slightly lower capacity and slightly higher compressor ratio at low temperature, may require a bigger compressor. Polyol ester lubricant required, two-three oil flushes. Conversion Retrofit Step 1. Establish base line data with CFC-12 or R-502 2. Remove CFC-12 or R-502 from system into recovery cylinder 3. Drain mineral oil 4. Charge system with approved lubricant 5. Replace filter drier 6. Evacuate the system 7. Charge with alternative refrigerant 8. Start up system and optimize charge The CFC File, (New Zealand) Issue 1, July 1993 Benefits R-134a is the best option for CFC-12 systems. DuPont's SUVA MP39 is another alternative, albeit interim because it contains HCFC-22. The price of HFC-134a has fallen by around 50% since the beginning of 1992, and should continue to fall as world-wide production increases. The price of CFCs is increasing world-wide, with CFC-12 doubling in price since January 1992. 1992 Davey, J.P, et al, Rhône-Poulenc, 1992: Field experience in retrofitting Isceon 134a and Isceons 69-S and 69-L. 37
Page 1 and 2: INFORMATION PAPER RETROFITTING WITH
Page 3 and 4: RETROFITTING WITH NON-CFC SUBSTITUT
Page 35: RETROFITTING WITH NON-CFC SUBSTITUT
Page 51: RETROFITTING WITH NON-CFC SUBSTITUT

retrofitting with non-cfc substitutes

Create successful ePaper yourself

Delete template?

Save as template?